(Mucopolysaccharidosis I S)
By: Alexa


Introduction and Description

Described by Harold Scheie, Scheie's syndrome is a mild variant of Hurler's syndrome, in which a person has a subnormal intelligence and dwarfism. However, people with Scheie's syndrome normally have average height and intelligence. They can also expect a normal life span, although these conditions are rather rare in Hurler's disease. "It is an uncommon hereditary metabolic disease" (britannica). Those with this disease may have any of the following characteristics: a delay in motor development, clawing of the hands, corneal clouding, a lacking aortic valve of the heart, carpal tunnel syndrome, or other skeletal deformities. These symptoms may occur as early as five years old, but since the disease is so mild, they may not be diagnosed well into adulthood. If you look at the following figures, you can see some differences between the average human hand (the picture on the left) and the hand of a person with Scheie disease (the picture on the right). The joint between the metacarpus and phalanges appear to be weaker in the picture on the right, the figures also seem less sturdy in the general area of the carpus.

external image bone-xray-hands.jpgexternal image cover_article_641_en_US.jpg

Molecular Basis

The syndrome is carried on a recessive gene, as a defect in the enzyme alpha-L-iduronidase. If both parents carry the defective IDUA gene, the child has a 25% chance of developing the disease. This missing substance, lysosomal alpha L-iduronidase, helps break down long chains of sugar molecules, or glycosaminoglycans. This enzyme is essential in the connection of developing tissues.The enzyme is typically found in mucus and fluid around the joints and the excess material can damage organs. A possible treatment for this disease would be enzyme replacement therapy or spinal cord compression.

Works Cited

http://www.britannica.com/EBchecked/topic/527171/Scheies-syndrome
http://www.nlm.nih.gov/medlineplus/ency/article/001246.htm
http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=93474